# -*- coding: utf-8 -*-
from copy import copy, deepcopy

a = [[1,2],3,4]

def f(a):
    a[-1] = 5
f(a) #改变
print(a)

b = [6,7]
a.append(b)
b[-1] = 8 #改变
print((a[-1]))

c = a[1:] 
c[0] = 9 #不改变
print(a)

d1 = [[]] * 5
d1[0].append(1)
print(d1)
d2 = [[] for _ in range(5)]
d2[0].append(1)
print(d2)


class C(object):
    def __init__(self, x=[]):
        pass
